Caratlane — Instead of repair the manufacturing defect they exchange the product and charged extra amount

Although the subject is not enough to elaborate my complain, so I write here in detail.
On 22 November 2021 I purchased a pair of earring from Caratlane City Center Guwahati worth Rs. 14218/- after getting discount of Rs. 250/-, I paid Rs. 13968/-. While using the product I have noticed that one of the earring lock is not worked properly, so on 25 November I went to Caratlane Bora Service G S Road to repair the same within the 14 days exchange/repair period. But there instead of repair the same they exchange the product and charged an extra amount of Rs. 127/-.
Although the problem can be solved by repairing, hence it is a manufacturing defect, I am not liable for that. I only there for fix the lock issue, not for exchange any other item. I should not charged extra. The amount may be very little, but it is about commitment. You shouldn't cheat your customer in this way.
I NEED AN ANSWER IMMEDIATELY OR ELSE I WILL HAVE TO KNOCK CONSUMER FORUM.